work bench lights

[tedmich]

Added some LED lights to the workbench

used 2x Samsung linear strips ($28 each) in 5000k (cold white) and 3500k (warmer) they're older units (SI-B8R521560WW) I had around but I'd use a SI-B8R52156CUS if I bought today ($18, 100Lm/$ more)

Their fed with Meanwell HLG-185H-48A unit I have a ton of (bought for $20 each) overkill here as the strips need only 100W, its dialed in for 48v CC

I attached the strips to 2" 1/8" thick U channels from McMC, riveted with heat transfer compound so they serve as heatsinks, and standoffs in case they get too hot for melamine shelf. I polished the inside wall and it serves as a decent reflector and keeps the 120 degree emission angle from blinding me as I approach, the spill is about 3 ft out onto the floor and should help me retrieve dropped screws etc.

I bongoed one strip with pop riveter, next time just Al rivets from OTHER side, as I used SS which require stupid force. I knocked out a couple SMD LEDs on the 5000k strip which (oddly) is twice as hot as 3500k one now (and also hooked it up reversed- sizzle POP, Doh! I may replace if it flames up)

While I LOVE very bright light, for dimming I added a 21kHz PWM unit from China, $15 and rated to 30A at 80V (maybe!) it even looks OK in digital photos!


I'll post links if anyone wants parts details.

[Enzo]

Idle question:

I always had four foot fluorescent fixtures, both overhead in the room, and also up under my bench riser. Some folks see flickering with fluorescents, I don't. But they DO strobe some, I note this when working on turntables. I have a pattered disc to toss on the platter, and some tables like the Techics 1200 have it built into the edge. With a neon light, the pattern locks in when the table rotates at proper speed.

The fluorescent lights strobe enough I can see the patterns. Not as strong as under neon, but visible, so I nevr needed to get out the neon.

I use LED lights in my home fixtures, but never in my shop, which closed a couple years ago.

So, do commercial LED lights strobe at all, or do they put out rock steady light? I don't mean so you notice visually, but a moving pattern might reveal any strobing.

[Leo_Gnardo]

So, do commercial LED lights strobe at all, or do they put out rock steady light? I don't mean so you notice visually, but a moving pattern might reveal any strobing.

Enzo I have a couple LED lamps on my workbench and yes, on occasion I have seen some strobe effect. One of them is a gooseneck with a pinch clamp so I can position it ideally for peering inside chassis. It induces a midrange oscillating noise @ 400 Hz. First time I heard it, I thought a tube had gone microphonic but the noise quit when the LED lamp was switched off. Similar noise from my LED Mag-lite.

[Helmholtz]

So, do commercial LED lights strobe at all, or do they put out rock steady light? I don't mean so you notice visually, but a moving pattern might reveal any strobing.

It all depends on the quality of the power supply (just as with discharge/fluorescent lamps). LEDs are current driven. Scoping the LED supply current will reveal if it contains low frequency ripple or amplitude modulation.

Easier is using a photocell as light sensor.

Sorry, if my answer doesn't really help.

[Enzo]

Thanks. I could detect it easy enough in a shop setting, but I no longer have a shop, and in my senior home, I cannot tell just looking at the lighting.

It hadn't occurred to me that the LED drive might be at its own freq rather than 60Hz. This was purely an academic question. If I were building today, I'd go with LED lights as well.

[Helmholtz]

It hadn't occurred to me that the LED drive might be at its own freq rather than 60Hz. This was purely an academic question. If I were building today, I'd go with LED lights as well.

Better quality LED luminaires contain SMPSs that supply the LEDs with smooth regulated DC current.
Quality electronic fluorescent/discharge ballasts operate with high frequency or square wave current and have boost SMPS converters at the mains input, which provide sine wave mains input current as well as a regulated DC supply to the voltage-current converter stage.

These types have negligible light modulation and max. efficiency/efficacy.

[eschertron]

It hadn't occurred to me that the LED drive might be at its own freq rather than 60Hz. This was purely an academic question. If I were building today, I'd go with LED lights as well.

On the one embedded uC system I designed, I used the standard-for-that-time/hardware PWM to control brightness. Any freq less than about 80Hz was detectable to me as an unnerving strobe effect if I moved my eyes from side-to-side. I'd expect 400Hz might be acceptable for even fast relative motion between LED and visual field.

Better quality LED luminaires contain SMPSs that supply the LEDs with smooth regulated DC current. These types have negligible light modulation and max. efficiency/efficacy.

Thank goodness for progress. Hardware-dependent, of course.

[Enzo]

When auto tail lights first started going to LED, many of them were strobed. As you said, moving your eye side to side would reveal a dotted line of red. More recent years have gone back to steady LEDs. I imagine because high intensity LEDs allow it, whereas they had to rest them by pulsing in earlier editions...or so it seems to me.

[g1]

Funny you mention that, just today I was looking at LED H4 auto bulbs, some had fans, some used heatsinks.

[blindboybenton]

Well as my name states, Im badly short sighted
I do struggle with getting enough bench light. I have found what's best for me is an angle poise with a 22 watt round tube 2700K
which i believe is a Cool white light , I have the ceiling light 100watt energy type and 60 watt lamp shining light from behind me right onto the bench

I'm looking to get a small LED torch fitted to the head set glasses i wear,
Im sorry to say that i think my eyes will give up and force me into retirement before i'm ready to hang up the soldering iron
I use to wear contact lenses in the workshop but now just glasses

SMD stuff is a bit of a struggle but i can still change those chips with 1000 legs

Blindboybenton

[Leo_Gnardo]

SMD stuff is a bit of a struggle but i can still change those chips with 1000 legs

If you can do those, you're way ahead of me.

There was a repair tech somewhere north of here, Saugerties NY IIRC, who adapted an overhead projector. He would perch his gadget above the item he was repairing, project its image on the adjacent wall, and got his work done that way. He managed to get done what needed to be done, for that I give him a lot of credit. A few years ago he moved to Florida. Can't blame him for that. Escaping from the snow & ice zone has its benefits.

Meanwhile I'm thinking of getting a head strap lantern like nevets. Plus a pair of zero-ground specs. I have the habit now of removing my bifocals because they're now of no use focusing at workbench distance, but I should have something on for safety's sake. And I really can't stand plastic safety goggles.

[Arbutt]

Before I started the amp repairs . I worked for a computer repair company. Learnt some and skills

I use a heat gun and metal tape. To get off the chip off